Need help with 08 silverado nav
 

Well I'm thinking I got the wrong nav unit but was hoping to run it by you guys to see if there's a work around. I bought a nav unit from eBay. Didn't get a part number for it before I bought it. So theres one mistake. They claimed it came out of a 08 silverado. So I get it and put it in and low n behold a Buick symbol shows up on the screen. So I try to relearn the vin with no success. The 06 monte trick didnt work on it. So I tried multiple ways with no success. I can get it to program module with y vin chosen and it went through relearn the vin but still says theft lock on display. Is there no way to reprogram this nav unit to work? Any info will be appreciated. Thanks!

Has no one come across this?